Excavator and control device

Abstract

To improve the efficiency of construction work. [Solution] The invention comprises a self-propelled lower traveling body, an upper rotating body rotatably mounted on the lower traveling body, an arm rotatably attached to a boom rotatably attached to the upper rotating body, a bucket rotatably attached to the arm, a tilt mechanism for tilting the bucket relative to the arm, a rotation mechanism for rotating the bucket relative to the arm, and a control device that enables simultaneous operation of the tilt of the bucket by the tilt mechanism and the rotation of the bucket by the rotation mechanism so that the target line passing through a predetermined position of the bucket is parallel to the excavation target surface.

Description

Technical Field

[0001] The present disclosure relates to an excavator and a control device.

Background Art

[0002] In recent years, an excavator equipped with a tilt-rotator mechanism has been known (for example, see Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Even in an excavator as described above, it is preferable to improve the efficiency of construction work.

Means for Solving the Problems

[0005] The excavator of the present disclosure includes a self-propelled lower traveling body, an upper revolving body rotatably provided on the lower traveling body, an arm rotatably attached to a boom rotatably attached to the upper revolving body, a bucket rotatably attached to the arm, a tilt mechanism for tilting the bucket with respect to the arm, a rotation mechanism for rotating the bucket with respect to the arm, and a control device that enables the bucket tilt by the tilt mechanism and the bucket rotation by the rotation mechanism to operate simultaneously so that the bucket line of the bucket is parallel to the excavation target surface.

[0006] Furthermore, an arm is rotatably attached to a boom that is rotatably attached to a rotating body, A bucket rotatably attached to the aforementioned arm, In an excavator having a control device for controlling the movement of the boom, arm, and bucket, The control device, A first mode in which the angle between the arm and the bucket is kept constant, A second mode in which the angle between the excavation target surface and the bottom surface of the bucket is kept constant, The system includes a third mode in which the target line passing through a predetermined position of the bucket is made parallel to the excavation target surface.

[0007] Furthermore, the control device of this disclosure is An arm rotatably attached to a boom that is rotatably attached to a slewing body, A bucket rotatably attached to the aforementioned arm, A tilt mechanism that tilts the bucket relative to the arm, A control device for an excavator having a rotation mechanism for rotating the bucket relative to the arm, The tilt mechanism allows the bucket to be tilted and the rotation mechanism allows the bucket to be rotated simultaneously. [Effects of the Invention]

[0008] According to this disclosure, it is possible to improve the efficiency of construction work. [Brief explanation of the drawing]

[0009] [Figure 1] This is a side view of an excavator according to one embodiment of the present invention. [Figure 2] Figure 1 is a block diagram showing the configuration of the excavator's drive system. [Figure 3] This is a block diagram showing the functional configuration of the controller. [Figure 4] This is a diagram illustrating the operation of the bucket. [Figure 5]It is a flowchart for explaining the process when enabling / disabling the control of the bucket. [Figure 6] It is a flowchart for explaining the process of making the bucket line along the bucket tip parallel to the excavation target surface by rotating the bucket. [Figure 7] FIG. is an example of a situation where the bucket line along the bucket tip cannot be made parallel to the excavation target surface even when the bucket 6 is tilted. [Figure 8] FIG. is an example of a situation where the bucket 6 is rotated to make the bucket line along the bucket tip parallel to the excavation target surface. [Figure 9] It is a flowchart for explaining the process of disabling the control of the enabled bucket 6. [Figure 10] FIG. is an example of a system in which the excavator is remotely operated. [Embodiments for Carrying Out the Invention] <8000087>

[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0011] [Configuration of Excavator] FIG. 1 is a side view of an excavator according to an embodiment.

[0012] As shown in FIG. 1, an upper swing body 3 is mounted on a lower traveling body 1 of an excavator 200 via a swing mechanism 2. A boom 4 is rotatably attached to the upper swing body 3. The lower traveling body 1 is capable of self-propulsion. An arm 5 is rotatably attached to the tip of the boom 4, and a bucket 6 as an end attachment is rotatably attached to the tip of the arm 5. As the end attachment, a slope bucket, a dredging bucket, etc. may be used.

[0013] The boom 4, arm 5, and bucket 6 constitute an excavation attachment as an example of an attachment, and are hydraulically driven by the boom cylinder 7, arm cylinder 8, and bucket cylinder 9, respectively. A boom angle sensor S1 is attached to the boom 4, an arm angle sensor S2 is attached to the arm 5, and a bucket angle sensor S3 is attached to the bucket 6. The boom angle sensor S1, arm angle sensor S2, and bucket angle sensor S3 are sometimes referred to as "attitude sensors." The bucket cylinder 9 is an example of a rotation mechanism in the present invention.

[0014] Furthermore, the shovel 200 is equipped with a tilt rotator 20 between the arm 5 and the bucket 6. The tilt rotator 20 allows the bucket 6 to be rotated in the left-right direction (width direction, yaw direction: hereinafter referred to as the tilt angle) with the center of the arm 5 as the pivot point, and also allows the angle of the bucket 6 around the axis of the base end (roll direction: hereinafter referred to as the roll angle).

[0015] Therefore, the tilt rotator 20 has a tilt mechanism 23 provided on the arm 5 side and a rotator mechanism 22 provided between the tilt mechanism 23 and the bucket 6. The tilt mechanism 23 includes a base 211 fixed to the arm 5, a tilt shaft 212 connected to the base 211, a support plate 213 that is pivotably supported relative to the tilt shaft 212, and a tilt actuator 214 that changes the tilt angle of the support plate 213. The tilt actuator 214 is composed of, for example, a pair of cylinder mechanisms with the tilt shaft 212 in between.

[0016] The rotator mechanism 22 includes a rotator motor 221 fixed to the support plate 213 of the tilt mechanism 23, a rotating shaft 222 rotated by the rotator motor 221, and a connecting part 223 connecting the rotating shaft 222 and the bucket 6. The rotating shaft 222 protrudes a short distance from the center of the support plate 213 and is connected to the connecting part 223. The connecting part 223 fixes the center of the base end of the bucket 6, and the roll angle of the bucket 6 is adjusted by rotating the bucket 6 around the central axis of the base end.

[0017] The excavator 200 rotates the entire tilt rotator 20 in the pitch direction as the arm cylinder 8 extends and retracts, thereby integrally changing the bucket angle (pitch angle) of the entire tilt rotator 20 and the bucket 6. Furthermore, the excavator 200 rotates the support plate 213 in the left-right direction relative to the base 211 as the tilt actuator 214 operates, thereby changing the tilt angle (yaw angle) of the bucket 6. For example, the tilt angle of the bucket 6 is adjusted within a range of 45° to the right to 45° to the left. Additionally, the working machine 100 rotates the connecting part 223 and the bucket 6 around an axis as the rotate motor 221 operates, thereby changing the roll angle of the bucket 6. For example, the roll angle of the bucket 6 is adjusted within a range of 360° relative to the support plate 213.

[0018] Furthermore, the tilt mechanism 23 has a bucket tilt angle sensor S5. The bucket tilt angle sensor S5 is a sensor that detects the rotation angle (tilt angle) of the bucket 6 around the tilt axis 212 and outputs the detected value. Furthermore, the rotator mechanism 22 has a rotate angle sensor S6. The rotate angle sensor S6 is a sensor that detects the angle (roll angle) around the axis of the base end of the bucket 6 and outputs the detected value.

[0019] The boom angle sensor S1 detects the rotation angle of the boom 4. In this embodiment, the boom angle sensor S1 is an acceleration sensor that detects the inclination with respect to the horizontal plane and detects the rotation angle of the boom 4 relative to the upper slewing body 3. The arm angle sensor S2 detects the rotation angle of the arm 5. In this embodiment, the arm angle sensor S2 is an acceleration sensor that detects the inclination with respect to the horizontal plane and detects the rotation angle of the arm 5 relative to the boom 4. The bucket angle sensor S3 detects the rotation angle of the bucket 6. In this embodiment, the bucket angle sensor S3 is an acceleration sensor that detects the inclination with respect to the horizontal plane and detects the rotation angle of the bucket 6 relative to the arm 5. The boom angle sensor S1, arm angle sensor S2, and bucket angle sensor S3 may be potentiometers using variable resistors, stroke sensors that detect the stroke amount of the corresponding hydraulic cylinder, rotary encoders that detect the rotation angle around the connecting pin, etc.

[0020] The upper rotating body 3 is equipped with a cabin 10 and a power source such as an engine 11. A tilt sensor S4 is also attached to the upper rotating body 3. The tilt sensor S4 is a sensor that detects the inclination of the upper rotating body 3 with respect to the horizontal plane. In this embodiment, the tilt sensor S4 is a two-axis acceleration sensor that detects the tilt angle of the upper rotating body 3 in the longitudinal and lateral directions. The tilt sensor S4 is sometimes referred to as an "attitude sensor".

[0021] The lower running body 1 is not limited to one using crawlers as shown in the figure; it may also be a wheeled shovel type with tires.

[0022] Inside the cabin 10, an input device D1, an audio output device D2, a display device D3, a storage device D4, a gate bar D5, and a controller 30 are installed.

[0023] The controller 30 is an example of a control device in the present invention and functions as a main control unit that controls the drive of the shovel. In this embodiment, the controller 30 is composed of a processing unit including a CPU and internal memory. Various functions of the controller 30 are realized by the CPU executing a program stored in the internal memory.

[0024] The input device D1 is a device for the operator of the shovel 200 to input various information. In this embodiment, the input device D1 is a membrane switch mounted on the surface of the display device D3. A touch panel or the like may also be used as the input device D1.

[0025] The audio output device D2 outputs various audio information in response to an audio output command from the controller 30. In this embodiment, an in-vehicle speaker directly connected to the controller 30 is used as the audio output device D2. Alternatively, an alarm device such as a buzzer may be used as the audio output device D2.

[0026] The display device D3 displays various image information in response to commands from the controller 30. In this embodiment, an in-vehicle liquid crystal display directly connected to the controller 30 is used as the display device D3.

[0027] The memory device D4 is a device for storing various types of information. In this embodiment, a non-volatile storage medium such as a semiconductor memory is used as the memory device D4. The memory device D4 stores various types of information output by the controller 30, etc.

[0028] The gate bar D5 is a mechanism that prevents the shovel 200 from being operated by mistake. In this embodiment, the gate bar D5 is positioned between the door of the cabin 10 and the driver's seat. When the gate bar D5 is raised to allow the operator to exit the cabin 10, the various operating devices become operable. On the other hand, when the gate bar D5 is pushed down to prevent the operator from exiting the cabin 10, the various operating devices become inoperable.

[0029] Figure 2 is a block diagram showing the configuration of the excavator's drive system as shown in Figure 1. In Figure 2, the mechanical power system is shown by double lines, the high-pressure hydraulic lines by thick solid lines, the pilot lines by dashed lines, and the electric drive and control system by thin solid lines.

[0030] Engine 11 is the power source for the shovel 200. In this embodiment, engine 11 is a diesel engine employing isochronous control to maintain a constant engine speed regardless of increases or decreases in engine load. The fuel injection amount, fuel injection timing, boost pressure, etc., in engine 11 are controlled by engine controller D7.

[0031] The engine controller D7 is a device that controls the engine 11. In this embodiment, the engine controller D7 performs various functions such as an auto idle function and an auto idle stop function.

[0032] The auto idle function is a function that reduces the engine speed from the normal speed (e.g., 2000 rpm) to the idle speed (e.g., 800 rpm) when predetermined conditions are met. In this embodiment, the engine controller D7 activates the auto idle function in response to the auto idle command from the controller 30 to reduce the engine speed to the idle speed.

[0033] The auto idle stop function is a function that stops the engine 11 when predetermined conditions are met. In this embodiment, the engine controller D7 activates the auto idle stop function in response to the auto idle stop command from the controller 30 and stops the engine 11.

[0034] Engine 11 is connected to a main pump 14 and a pilot pump 15, which function as hydraulic pumps. A control valve 17 is connected to the main pump 14 via a high-pressure hydraulic line 16.

[0035] The control valve 17 is a hydraulic control device that controls the hydraulic system of the excavator. Hydraulic actuators such as the right-side travel hydraulic motor 1A, the left-side travel hydraulic motor 1B, the boom cylinder 7, the arm cylinder 8, the bucket cylinder 9, the slewing hydraulic motor 21, and the tilt bucket cylinder 64 are connected to the control valve 17 via the high-pressure hydraulic line 16.

[0036] An operating device 26 is connected to the pilot pump 15 via a pilot line 25 and a gate lock valve D6. A control valve 17 is also connected to the pilot pump 15 via a pilot line 25A and a switching valve D8. The operating device 26 includes levers 26A and 26B, and a pedal 26C. In this embodiment, the operating device 26 is connected to the control valve 17 via a hydraulic line 27. A pressure reducing valve V1, controlled by a controller 30, is provided in the hydraulic line 27. The operating device 26 is also connected to an operating sensor 29 via a hydraulic line 28.

[0037] The gate lock valve D6 switches the connection and disconnection of the pilot line 25 connecting the pilot pump 15 and the operating device 26. In this embodiment, the gate lock valve D6 is a solenoid valve that switches the connection and disconnection of the pilot line 25 in response to a command from the controller 30. The controller 30 determines the state of the gate bar D5 based on the state signal output by the gate bar D5. When the controller 30 determines that the gate bar D5 is in the lowered state, it outputs a connection command to the gate lock valve D6. Upon receiving the connection command, the gate lock valve D6 opens and connects the pilot line 25. As a result, the operator's operation of the operating device 26 becomes effective. On the other hand, when the controller 30 determines that the gate bar D5 is in the raised state, it outputs a disconnection command to the gate lock valve D6. Upon receiving the disconnection command, the gate lock valve D6 closes and disconnects the pilot line 25. As a result, the operator's operation of the operating device 26 becomes ineffective.

[0038] The switching valve D8 switches the connection and disconnection of the pilot line 25A, which connects the pilot pump 15 and the control valve 17. In this embodiment, the switching valve D8 is an electromagnetic proportional valve that switches the connection and disconnection of the pilot line 25A in response to a command from the controller 30. The controller 30 uses the switching valve D8 to switch the connection and disconnection of the pilot line 25A during the tilt and rotation operation of the bucket 6, which will be described later, to hydraulically drive or not drive the bucket cylinder 9 and the tilt bucket cylinder 64.

[0039] The operation sensor 29 detects the operation content corresponding to the operation of the operating device 26. The operation sensor 29 outputs the detected operation content to the controller 30.

[0040] Next, with reference to Figure 3, the various functional elements provided in the controller 30 will be explained. Figure 3 is a functional block diagram showing the configuration of the controller 30.

[0041] In this embodiment, the controller 30 controls the operation of the entire shovel 200.

[0042] The controller 30 receives various signals and data output from the boom angle sensor S1, arm angle sensor S2, bucket angle sensor S3, machine tilt sensor S4, bucket tilt angle sensor S5, and input device D1. Based on the received signals and data, the controller 30 calculates the actual operating position of the attachment (e.g., bucket 6). If the actual operating position of the attachment differs from the target operating position, the controller 30 sends an alarm command to the voice output device D2 and display device D3 to issue an alarm.

[0043] The controller 30 includes a functional unit that performs various functions. In this embodiment, the controller 30 has a target tilt angle calculation unit 31, a followability determination unit 32, a bucket state determination unit 33, a tilt angle control unit 34, and a rotation angle control unit 35 as functional units for controlling the operation of the attachment.

[0044] The target tilt angle calculation unit 31 calculates the direction and angle by which the bucket 6 should be tilted so that the bucket line of the bucket 6 becomes parallel to the excavation target surface. The bucket line is an example of a target line in the present invention and refers to the line along the tip of the bucket 6. In this embodiment, the bucket angle sensor S3 detects the inclination of the bucket 6 with respect to the horizontal plane. The bucket tilt angle sensor S5 detects the rotation angle (tilt angle) of the bucket 6 around the tilt axis 212. The angle of the excavation target surface is stored in the storage device D4 as construction information. Therefore, the target tilt angle calculation unit 31 can calculate the direction and angle by which the bucket 6 should be tilted so that the bucket line along the tip of the bucket 6 becomes parallel to the excavation target surface, based on the detection results of the bucket angle sensor S3 and the bucket tilt angle sensor S5 and the construction information stored in the storage device D4.

[0045] In this embodiment, the target line was described using the bucket line along the tip of the bucket 6 as an example. However, the target line is not limited to the bucket line along the tip of the bucket 6. For example, when the bucket 6 is in a closed state, the bottom surface of the bucket 6 is closer to the target surface than the tip of the bucket 6, so the target line may include the bottom surface of the bucket 6. In addition, it may pass through a predetermined position of the bucket 6 that has been set in advance.

[0046] The followability determination unit 32 determines whether the bucket 6 can be tilted in the direction and at the angle calculated by the target tilt angle calculation unit 31. Depending on the relative orientation of the bucket 6 with respect to the excavation target surface, even if the bucket 6 is tilted, it may not be possible to make the bucket line along the tip of the bucket 6 parallel to the excavation target surface. For example, if there is an uphill excavation target surface in front of the shovel 200 and the bucket 6 is facing sideways, the axial direction of the tilt axis for tilting the bucket 6 is directed forward from the shovel 200, even when the bucket 6 is facing sideways. Therefore, simply tilting the bucket 6 will not make the bucket line along the tip of the bucket 6 parallel to the excavation target surface. The followability determination unit 32 determines whether simply tilting the bucket 6 will allow the bucket line along the tip of the bucket 6 to follow the excavation target surface so that the bucket line along the tip of the bucket 6 becomes parallel to the excavation target surface.

[0047] The bucket state determination unit 33 determines the distance and orientation of the bucket 6 with respect to the excavation target surface, and determines whether the distance between the bottom surface 6b of the bucket 6 and the excavation target surface is less than or equal to a predetermined value. In this embodiment, the bucket angle sensor S3 detects the inclination of the bucket 6 with respect to the horizontal plane. The boom angle sensor S1 detects the inclination of the boom 4 with respect to the horizontal plane. The arm angle sensor S2 detects the inclination of the arm 5 with respect to the horizontal plane. The machine body inclination sensor S4 detects the inclination of the upper slewing body 3 with respect to the horizontal plane. Information on the excavation target surface is stored in the storage device D4 as construction information. Therefore, the bucket state determination unit 33 can determine the distance and orientation of the bucket 6 with respect to the excavation target surface based on the detection results of the bucket angle sensor S3, boom angle sensor S1, arm angle sensor S2, and machine body inclination sensor S4, and the construction information stored in the storage device D4.

[0048] If the Followability Determination Unit 32 determines that the bucket line along the tip of the bucket 6 can be made to follow the excavation target surface simply by tilting the bucket 6, the tilt angle control unit 34 tilts the bucket 6 in the direction and angle calculated by the Target Tilt Angle Calculation Unit 31. Specifically, the tilt angle control unit 34 opens the switching valve D8 to connect the pilot line 25A and hydraulically drives the tilt bucket cylinder 64 via the control valve 17 so that the bucket 6 tilts in the direction and angle calculated by the Target Tilt Angle Calculation Unit 31. Furthermore, even if the Followability Determination Unit 32 determines that the bucket line along the tip of the bucket 6 cannot be made parallel to the excavation target surface simply by tilting the bucket 6, the tilt angle control unit 34 tilts the bucket 6 to the limit where the line along the tip of the bucket 6, which is the bucket line, is parallel to the excavation target surface. The adjustment range of the tilt angle of the bucket 6 may be set, for example, to ±45°. In that case, if the angle calculated by the target tilt angle calculation unit 31 is 50°, simply tilting the bucket 6 will not be enough to make the bucket line along the tip of the bucket 6 follow the excavation target surface so that it is parallel to it. Even in such a case, the tilt angle control unit 34 tilts the bucket 6 to its limit of 45°.

[0049] If the tracking feasibility determination unit 32 determines that simply tilting the bucket 6 is insufficient to make the bucket line along the tip of the bucket 6 follow the excavation target surface, the rotation angle control unit 35 rotates the bucket 6 by driving the bucket cylinder 9 so that the bucket line along the tip of the bucket 6 becomes parallel to the excavation target surface. Specifically, the rotation angle control unit 35 opens the switching valve D8 to connect the pilot line 25A and hydraulically drives the bucket cylinder 9 via the control valve 17 so that the bucket 6 rotates so that the bucket line along the tip of the bucket 6 becomes parallel to the excavation target surface. At this time, the rotation angle control unit 35 calculates the amount of rotation of the bucket 6 by the bucket cylinder 9 to make the bucket line along the tip of the bucket 6 parallel to the excavation target surface based on the amount of tilt of the bucket 6 by the tilt angle control unit 34, and rotates the bucket 6 by driving the bucket cylinder 9 by that amount of rotation.

[0050] [Shovel operation] The operation of the Shovel 200, configured as described above, is explained below.

[0051] First, let's explain the operation of bucket 6.

[0052] Figure 4 is a diagram illustrating the operation of bucket 6.

[0053] The excavator 200 shown in Figure 1 is equipped with a so-called tilt rotator mechanism. Therefore, the bucket 6 can be rotated not only in one direction relative to the arm 5, but also in two other directions.

[0054] Specifically, as shown in Figure 4, the bucket 6 can be rotated around the bucket axis formed by the bucket pin 61 in the direction of arrow E1 in the figure, which is the direction in which the bucket 6 is opened and closed. This rotation can be achieved by hydraulically driving the bucket cylinder 9.

[0055] Furthermore, the bucket 6 can be rotated in the direction of arrow E2 in the figure, around a rotation axis that extends in the direction connecting the arm 5 and the bucket 6.

[0056] Furthermore, the bucket 6 can be rotated in the direction of arrow E3 in the figure, around the tilt axis, in the direction that tilts the bucket 6. This rotation can be achieved by hydraulically driving the tilt bucket cylinder 64.

[0057] The rotation of these buckets 6 can be performed based on operations on the operating device 26, but it can also be performed in response to commands from the controller 30. As shown in Figure 1, the tilt actuator 214 and tilt shaft 212 are located on the tip side of the bucket 6 beyond the bucket cylinder 9, and the rotate motor 221 and rotating shaft 222 are located on the tip side of the bucket 6 beyond the tilt shaft 212. This means that the tilt shaft is located at the end of the bucket shaft, and the rotate shaft is located at the end of the tilt shaft. In other words, when the bucket 6 is rotated by the bucket cylinder 9, the tilt shaft 212 and rotating shaft 222 also rotate. Also, when the bucket 6 is rotated (tilted) by the tilt actuator 214, the rotating shaft 222 also rotates.

[0058] Next, we will explain the process of enabling / disabling control of bucket 6.

[0059] In the excavator 200 described above, the control of bucket 6 is enabled or disabled from the perspective of construction efficiency. When the control of bucket 6 is disabled, construction by the excavator 200 is mainly carried out by operating the boom 4 and arm 5. When construction is carried out by operating the boom 4 and arm 5 without operating bucket 6, construction can be carried out quickly over a wide area due to reasons such as ease of operation. On the other hand, when excavating the target surface, it is necessary to operate bucket 6. Therefore, when the bottom surface 6b of bucket 6 is far from the target surface, the control of bucket 6 is disabled, and when the bottom surface 6b of bucket 6 approaches the target surface, the control of bucket 6 is enabled.

[0060] Figure 5 is a flowchart illustrating the process of enabling / disabling control of bucket 6.

[0061] In this process, first, the bucket state determination unit 33 determines the distance and orientation of the bucket 6 with respect to the excavation target surface and calculates the distance between the bottom surface 6b of the bucket 6 and the excavation target surface (step ST11). Here, as described above, the bucket angle sensor S3 detects the inclination of the bucket 6 with respect to the horizontal plane, the boom angle sensor S1 detects the inclination of the boom 4 with respect to the horizontal plane, and the arm angle sensor S2 detects the inclination of the arm 5 with respect to the horizontal plane. In addition, the machine body tilt sensor S4 detects the inclination of the upper slewing body 3 with respect to the horizontal plane, and information on the excavation target surface is stored in the storage device D4 as construction information. Therefore, the bucket state determination unit 33 can determine the distance and orientation of the bucket 6 with respect to the excavation target surface based on the detection results of the bucket angle sensor S3, boom angle sensor S1, arm angle sensor S2, and machine body tilt sensor S4, and the construction information stored in the storage device D4.

[0062] Then, the bucket state determination unit 33 determines whether the distance between the bottom surface 6b of the bucket 6 and the excavation target surface is less than or equal to a predetermined value (step ST12). If the distance between the bottom surface 6b of the bucket 6 and the excavation target surface is not less than or equal to the predetermined value (NO in step ST12), the controller 30 disables control of the bucket 6 (step ST13). When control of the bucket 6 is disabled, the bucket 6 is not rotated by the bucket cylinder 9. In addition, of the tilt angle control unit 34 and the rotation angle control unit 35, the bucket 6 can be tilted by the tilt angle control unit 34, but it is not possible to rotate the bucket 6 by driving the bucket cylinder 9 with the rotation angle control unit 35. In this case, the controller 30 enters a first mode in which the angle between the arm 5 and the bucket 6 is kept constant regardless of the angle between the bottom surface 6b of the bucket 6 and the excavation target surface. In the first mode, for example, work such as excavating the excavation target surface is performed.

[0063] On the other hand, if the distance between the bottom surface 6b of the bucket 6 and the excavation target surface is less than or equal to a predetermined value (YES in step ST12), the controller 30 activates control of the bucket 6 (step ST14). When control of the bucket 6 is activated, it becomes possible to rotate the bucket 6 by driving the bucket cylinder 9. In addition, of the tilt angle control unit 34 and the rotation angle control unit 35, both the tilt angle control unit 34 allows tilting of the bucket 6 and the rotation angle control unit 35 allows rotation of the bucket 6 by driving the bucket cylinder 9. In this case, the controller 30 enters a second mode in which the angle between the arm 5 and the bucket 6 is variable, and the angle between the tip of the bucket 6 and the excavation target surface is kept constant. In the second mode, for example, work such as leveling the excavation target surface is performed.

[0064] In this way, the control of the bucket 6 is enabled or disabled based on the distance between the bottom surface 6b of the bucket 6 and the excavation target surface.

[0065] Furthermore, if the machine control function by controller 30 is disabled, control of bucket 6 will be disabled.

[0066] On the other hand, if the machine control function by the controller 30 is enabled and permission is granted to operate the bucket 6, then, as described above, if the distance between the bottom surface 6b of the bucket 6 and the excavation target surface is less than or equal to a predetermined value, the control of the bucket 6 by the rotation angle control unit 35 is enabled, and the angle between the bottom surface 6b of the bucket 6 and the excavation target surface is controlled to remain constant.

[0067] Furthermore, even if the machine control function by the controller 30 is enabled and permission is granted to operate the bucket 6, if the distance between the bottom surface 6b of the bucket 6 and the excavation target surface is not below a predetermined value, the control of the bucket 6 by the rotation angle control unit 35 is disabled, and the angle between the arm 5 and the bucket 6 is kept constant.

[0068] Next, we will explain the process of rotating the bucket 6 to make the line of the bucket 6's tip parallel to the excavation target surface when simply tilting the bucket 6 is insufficient.

[0069] Figure 6 is a flowchart illustrating the process of rotating the bucket 6 to align the bucket line along the tip of the bucket 6 with the excavation target surface.

[0070] In this process, first, the target tilt angle calculation unit 31 calculates the direction and angle at which to tilt the bucket 6 so that the bucket line along the tip of the bucket 6 is parallel to the excavation target surface (step ST21). At this time, the bucket angle sensor S3 detects the inclination of the bucket 6 with respect to the horizontal plane, and the bucket tilt angle sensor S5 detects the rotation angle of the bucket 6 around the tilt axis. In addition, the angle of the excavation target surface is stored in the storage device D4 as construction information. Therefore, the target tilt angle calculation unit 31 can calculate the direction and angle at which to tilt the bucket 6 so that the bucket line along the tip of the bucket 6 is parallel to the excavation target surface, based on the detection results of the bucket angle sensor S3 and the bucket tilt angle sensor S5 and the construction information stored in the storage device D4.

[0071] Next, the followability determination unit 32 determines whether the bucket 6 can be tilted in the direction and at the angle calculated by the target tilt angle calculation unit 31 (step ST22). As described above, depending on the relative orientation of the bucket 6 with respect to the excavation target surface, even if the bucket 6 is tilted, it may not be possible to make the line of the bucket tip parallel to the excavation target surface. Therefore, the followability determination unit 32 determines whether the bucket line along the tip of the bucket 6 can be made parallel to the excavation target surface simply by tilting the bucket 6.

[0072] Figure 7 shows an example of a situation where, even when the bucket 6 is tilted, the bucket line along the tip of the bucket 6 cannot be made parallel to the excavation target surface.

[0073] As shown in Figure 7, when there is an uphill excavation target surface GL in front of the shovel 200 and the bucket 6 is facing sideways, the axial direction of the tilt axis A1 for tilting the bucket 6 is oriented in the front-to-back direction of the shovel 200, even when the bucket 6 is facing sideways. Therefore, simply tilting the bucket 6 does not make the bucket line along the tip 6a of the bucket 6 parallel to the excavation target surface GL.

[0074] Therefore, if the bucket 6 cannot be tilted to the direction and angle calculated by the target tilt angle calculation unit 31 (NO in step ST22), the controller 30 first determines whether it is in the first mode in which the control by driving the bucket cylinder 9 of the bucket 6 in the rotation angle control unit 35 is disabled (step ST23).

[0075] In the first mode, where the control of the bucket cylinder 9 of the bucket 6 by the rotation angle control unit 35 is disabled, as described above, the bucket 6 can be tilted by the tilt angle control unit 34, but it is not possible to rotate the bucket 6 by the rotation angle control unit 35. Therefore, if the bucket 6 cannot be tilted in the direction and angle calculated by the target tilt angle calculation unit 31, the bucket line along the tip 6a of the bucket 6 cannot be made parallel to the excavation target surface GL. For example, when performing construction with the tip 6a of the bucket 6 positioned in line with the excavation target surface GL, the control of the bucket 6 is disabled because the bottom surface 6b of the bucket 6 is away from the excavation target surface GL. In this state, if the bucket 6 cannot be tilted in the direction and angle calculated by the target tilt angle calculation unit 31, the bucket line along the tip 6a of the bucket 6 cannot be made parallel to the excavation target surface GL, and construction cannot be performed.

[0076] Therefore, if the control of the bucket 6 in the rotation angle control unit 35 is disabled (YES in step ST23), the controller 30 enables the control of the bucket 6 by driving the bucket cylinder 9 in the rotation angle control unit 35 (step ST24). In this case, the controller 30 enters a third mode in which the bucket line along the tip 6a of the bucket 6 is made parallel to the excavation target surface GL.

[0077] Then, the tilt angle control unit 34 tilts the bucket 6 to its limit, and the rotation angle control unit 35 rotates the bucket 6 until the bucket line along the tip 6a of the bucket 6 is parallel to the excavation target surface GL. At this time, as described above, the rotation angle control unit 35 calculates the amount of rotation of the bucket 6 required to make the bucket line along the tip 6a of the bucket 6 parallel to the excavation target surface GL based on the amount of tilt of the bucket 6 by the tilt angle control unit 34, and rotates the bucket 6 by driving the bucket cylinder 9 by that amount of rotation.

[0078] Thus, in this embodiment, the excavator 200 has an arm 5 rotatably attached to a boom 4 rotatably attached to an upper rotating body 3, a bucket 6 rotatably attached to the arm 5, and a controller 30 that controls the operation of the boom 4, arm 5 and bucket 6. The controller 30 has a first mode that maintains a constant angle between the arm 5 and the bucket 6, a second mode that maintains a constant angle between the excavation target surface and the bottom surface 6b of the bucket 6, and a third mode that makes the bucket line of the bucket 6 parallel to the excavation target surface.

[0079] Figure 8 shows an example of a situation where the bucket 6 is rotated so that the bucket line along the tip 6a of the bucket 6 is parallel to the excavation target surface. As shown in Figure 8, when there is an uphill excavation target surface GL in front of the shovel 200 and the bucket 6 is facing sideways, the axial direction of the bucket axis A2 for rotating the bucket 6 is perpendicular to the front-to-back direction of the shovel 200, even when the bucket 6 is facing sideways. Therefore, by rotating the bucket 6, the bucket line along the tip 6a of the bucket 6 can be made parallel to the excavation target surface GL.

[0080] Furthermore, if the bucket 6 can be tilted to the direction and angle calculated by the target tilt angle calculation unit 31 (YES in step ST22), it is not necessary to enable control of the bucket 6. Also, if the control of the bucket 6 is already enabled (NO in step ST23), it is not necessary to enable control of the bucket 6 again.

[0081] Thus, even in a configuration that disables the control of the bucket 6 when the bottom surface 6b of the bucket 6 is far from the excavation target surface from the standpoint of construction efficiency, if simply tilting the bucket 6 does not make the bucket line along the tip 6a of the bucket 6 parallel to the excavation target surface, the control of the bucket 6 can be temporarily enabled, allowing construction to be performed with the tip 6a of the bucket 6 relative to the excavation target surface.

[0082] As described above, in this embodiment, in order to control the shovel 200 having an arm 5 rotatably attached to a boom 4 rotatably attached to an upper slewing body 3, a bucket 6 rotatably attached to the arm 5, a tilt mechanism 23 for tilting the bucket 6 relative to the arm 5, and a bucket cylinder 9 for rotating the bucket 6 relative to the arm 5, there is a controller 30 that simultaneously operates the tilt of the bucket 6 by the tilt mechanism 23 and the rotation of the bucket 6 by the bucket cylinder 9 so that the bucket line of the bucket 6 is parallel to the excavation target surface. This makes it possible to improve the efficiency of construction work. Furthermore, in this case, the controller 30 has a first mode in which the angle between the arm 5 and the bucket 6 is kept constant, a second mode in which the angle between the excavation target surface and the bottom surface 6b of the bucket 6 is kept constant, and a third mode in which the bucket line of the bucket 6 is made parallel to the excavation target surface, so that the efficiency of construction work can be improved by changing the mode of the controller 30.

[0083] Furthermore, if the bucket line of the bucket 6 is not parallel to the excavation target surface due to the tilt of the bucket 6 by the tilt mechanism 23, the controller 30 operates the bucket cylinder 9 to rotate the bucket 6 so that the bucket line of the bucket 6 becomes parallel to the excavation target surface. In this way, even if the line of the tip 6a of the bucket 6 cannot be made parallel to the excavation target surface by tilting the bucket 6 alone, the line of the tip 6a of the bucket 6 can be made to follow the excavation target surface by rotating the bucket 6 and become parallel to the excavation target surface.

[0084] Furthermore, the controller 30 enables simultaneous operation of the tilt mechanism 23 to tilt the bucket 6 and the bucket cylinder 9 to rotate the bucket 6 when predetermined conditions are met. With this configuration, the tilt mechanism 23 to tilt the bucket 6 and the bucket cylinder 9 to rotate the bucket 6 can be operated simultaneously only when necessary.

[0085] Here, the configuration for disabling bucket 6 is provided from the viewpoint of construction efficiency, as described above. Therefore, it is preferable that it be temporary. The process for disabling the control of the enabled bucket 6 is described below.

[0086] Figure 9 is a flowchart illustrating the process of deactivating control of the enabled bucket 6.

[0087] In this process, first, similar to the process in step ST21, the target tilt angle calculation unit 31 calculates the direction and angle at which the bucket 6 should be tilted so that the line along the tip of the bucket, which is the bucket line of the bucket 6, is parallel to the excavation target surface (step ST31).

[0088] Next, similar to the process in step ST22, the tracking feasibility determination unit 32 determines whether the bucket 6 can be tilted in the direction and angle calculated by the target tilt angle calculation unit 31 (step ST32).

[0089] Then, if the bucket 6 can be tilted in the direction and angle calculated by the target tilt angle calculation unit 31 (YES in step ST32), the bucket state determination unit 33 determines the distance and orientation of the bucket 6 relative to the excavation target surface, and calculates the distance between the bottom surface 6b of the bucket 6 and the excavation target surface, similar to the process in step ST11 (step ST33).

[0090] Then, the bucket state determination unit 33 determines whether the distance between the bottom surface 6b of the bucket 6 and the excavation target surface is less than or equal to a predetermined value (step ST34), similar to the process in step ST12. If the distance between the bottom surface 6b of the bucket 6 and the excavation target surface is not less than or equal to the predetermined value (NO in step ST34), the control of the bucket 6 is disabled (step ST35).

[0091] On the other hand, if the bucket 6 cannot be tilted to the direction and angle calculated by the target tilt angle calculation unit 31 (NO in step ST32), the control of the bucket 6 is not deactivated because the bucket line along the tip of the bucket 6 cannot be made parallel to the excavation target surface unless the bucket 6 is rotated.

[0092] Furthermore, if the distance between the bottom surface 6b of bucket 6 and the excavation target surface is less than or equal to a predetermined value (YES in step ST34), the conditions for enabling the control of bucket 6 are already met, and therefore the control of bucket 6 is not disabled.

[0093] In this way, the controller 30 disables the rotation of the bucket 6 by the bucket cylinder 9 when the predetermined conditions are no longer met. This allows for the control of the bucket 6 to be disabled when the predetermined conditions are no longer met, thereby improving construction efficiency.

[0094] Furthermore, the shovel 200 may be configured such that some or all of its driven elements, such as the lower traveling body 1, upper slewing body 3, boom 4, arm 5, and bucket 6, are electrically driven by electric actuators. In other words, the shovel 200 may be a hybrid shovel or an electric shovel.

[0095] (Other embodiments) Instead of being configured to be operated by an operator sitting in the cabin 10, or in addition to being configured to be remotely operated from outside the shovel 200, the shovel 200 may also be configured to be remotely operated. When the shovel 200 is remotely operated, the interior of the cabin 10 may be unoccupied.

[0096] Figure 10 shows an example of a system in which the 200 shovel is remotely controlled.

[0097] As shown in Figure 10, the shovel 200 may be operated from a remote control room RC.

[0098] The remote control room RC is equipped with a remote controller 40, a sound output device RD2, an indoor imaging device RC1, a display device RD3, and a communication device T. The remote control room RC also has a driver's seat DS where the operator OP sits to remotely control the shovel 200.

[0099] The remote controller 40 is an example of a control device in the present invention and is an arithmetic unit that performs various calculations. In this embodiment, the remote controller 40, like the controller 30, is composed of a microcomputer including a CPU and memory. The various functions of the remote controller 40 are realized by the CPU executing a program stored in memory.

[0100] The sound output device RD2 is configured to output sound. In this embodiment, the sound output device RD2 is a speaker and is configured to reproduce the sound collected by a sound collection device (not shown) attached to the shovel 200.

[0101] The indoor imaging device RC1 is configured to image the inside of the remote control room RC. In this embodiment, the indoor imaging device RC1 is a camera installed inside the remote control room RC and is configured to image the operator OP seated in the driver's seat DS.

[0102] The communication device T is configured to control wireless communication with a communication device (not shown) attached to the shovel 200.

[0103] A remote control device 126, including an engine speed adjustment dial 75, is provided near the driver's seat DS. The engine speed adjustment dial 75 is a dial for adjusting the rotational speed of the engine 11, and is configured to allow switching of the engine speed in four stages, for example, SP mode, H mode, A mode, and idling mode. The remote control device 126 is equipped with an operation sensor 129 that detects the operation of the remote control device 126. This allows detection of the operation of the remote control device 126. In addition to a pressure sensor that detects pressure on the remote control device 126, the sensor for detecting the operation of the remote control device 126 may also be a tilt sensor that detects the tilt angle of the operation lever, or an angle sensor that detects the swing angle around the pivot axis of the operation lever. Furthermore, the sensor for detecting the operation of the remote control device 126 may consist of other sensors such as a pressure sensor, a current sensor, a voltage sensor, or a distance sensor. The operation sensor 129 outputs the detected pressure value to the remote controller 40. The remote controller 40 generates an operation signal based on the received pressure value and transmits the generated operation signal to the shovel 200.

[0104] The display device RD3 is configured to display information about the surrounding conditions of the shovel 200. In this embodiment, the display device RD3 is a multi-display consisting of nine monitors arranged in three vertical rows and three horizontal columns, and is configured to display the conditions of the space in front of, to the left of, and to the right of the shovel 200. Each monitor is an LCD monitor or an OLED monitor, etc. However, the display device RD3 may consist of one or more curved monitors or may consist of a projector.

[0105] The display device RD3 may be a display device that can be worn by the operator OP. For example, the display device RD3 may be a head-mounted display and may be configured to send and receive information to and from the remote controller 40 via wireless communication. The head-mounted display may be wired to the remote controller 40. The head-mounted display may be a transparent head-mounted display or an opaque head-mounted display. The head-mounted display may be a monocular head-mounted display or a binocular head-mounted display.

[0106] The display device RD3 is configured to display images that allow the operator OP in the remote control room RC to visually inspect the area around the shovel 200. In other words, the display device RD3 displays images that allow the operator to check the situation around the shovel 200 as if they were inside the cabin 10 of the shovel 200, even though they are in the remote control room RC.

[0107] In a remote control room RC configured in this way, the remote controller 40 may also be equipped with the functions of the functional unit of the controller 30 of the shovel 200, which consists of a target tilt angle calculation unit 31, a tracking feasibility determination unit 32, a bucket state determination unit 33, a tilt angle control unit 34, and a rotation angle control unit 35, and perform the automatic bucket tilt control described above. [Explanation of Symbols]

[0108] 1. Lower running body 2. Swivel mechanism 3. Upper rotating body 4 Boom 5 Arms 6 buckets 6a Toenail 6b Bottom 7 Boom Cylinder 8 Arm Cylinder 9 Bucket Cylinder 10 cabins 11 Engine 14 Main pump 15 Pilot pump 16 High-pressure hydraulic line 17 Control valve 20 Tilt Rotator 22 Rotator mechanism 23 Tilt mechanism 26 Operating device 29,129 Operation Sensors 30 controllers 31 Target Tilt Angle Calculation Unit 32. Followability determination unit 33 Bucket status determination unit 34 Tilt Angle Control Unit 35 Rotation Angle Control Unit 40 Remote Controllers 126 Remote control device 200 Shovel 212 Tilt axis 214 Tilt Actuator 221 Rotating Motor 222 Rotating shaft A1 Tilt axis A2 Bucket shaft S1 Boom Angle Sensor S2 Arm Angle Sensor S3 Bucket Angle Sensor S4 Aircraft tilt sensor S5 Bucket Tilt Angle Sensor S6 Rotator Angle Sensor D1 Input Device D2, RD2 Audio Output Device D3, RD3 Display Device D4 storage device D5 Gate Bar D6 Gate Lock Valve D7 Engine Controller D8 Switching valve RC1 Indoor Imaging Device T Communication device GL (Ground Level) Excavation Target Surface

Claims

1. A self-propelled lower vehicle, An upper rotating body is provided on the lower traveling body so as to be rotatable, An arm rotatably attached to a boom rotatably attached to the upper rotating body, A bucket rotatably attached to the aforementioned arm, A tilt mechanism that tilts the bucket relative to the arm, A rotating mechanism that rotates the bucket relative to the arm, An excavator having a control device that enables simultaneous operation of the tilt of the bucket by the tilt mechanism and the rotation of the bucket by the rotation mechanism, such that the target line passing through a predetermined position of the bucket is parallel to the excavation target surface.

2. The excavator according to claim 1, wherein the target line is a bucket line that follows the tip of the bucket.

3. The excavator according to claim 1, wherein the control device operates the rotation mechanism to rotate the bucket so that the target line of the bucket becomes parallel to the excavation target surface when the tilt of the bucket by the tilt mechanism does not make the target line of the bucket parallel to the excavation target surface.

4. The excavator according to claim 1, wherein the control device enables simultaneous operation of the tilt of the bucket by the tilt mechanism and the rotation of the bucket by the rotation mechanism when predetermined conditions are met.

5. The excavator according to claim 4, wherein the control device disables the rotation of the bucket by the rotation mechanism when the predetermined conditions are no longer met.

6. An arm rotatably attached to a boom that is rotatably attached to a slewing body, A bucket rotatably attached to the aforementioned arm, In an excavator having a control device for controlling the movement of the boom, arm, and bucket, The control device, A first mode in which the angle between the arm and the bucket is kept constant, A second mode in which the angle between the excavation target surface and the bottom surface of the bucket is kept constant, A shovel comprising a third mode in which the target line passing through a predetermined position of the bucket is made parallel to the excavation target surface.

7. An arm rotatably attached to a boom that is rotatably attached to a slewing body, A bucket rotatably attached to the aforementioned arm, A tilt mechanism that tilts the bucket relative to the arm, A control device for an excavator having a rotation mechanism for rotating the bucket relative to the arm, A control device that enables simultaneous operation of the tilt of the bucket by the tilt mechanism and the rotation of the bucket by the rotation mechanism.

Images